Facebook already wanted to know what you were doing, now they want to know where you’re doing it Facebook Places is a new service that lets you report where you are as you go through your day. It’s the company’s long anticipate foray into geolocation, a sort of melding of cyberspace and “meatspace” that a lot of people think will become very popular.

But it’s probably a good idea to know exactly what you’re sharing and what you’re keeping private, especially since that’s a line that has been a bit shaky on Facebook in the past.

We talk to CNET’s Molly Wood about how Places work so you can get a better handle on how to use it. We also talk to video editor Bill Cammack who posted on his web site instructions on opting out of the “location tagging” section of Places. He walks us through that.